The Guide
The Male Factor
- Male factor is involved in roughly 40 to 50% of infertility cases — but the conversation almost always focuses on the woman
- A normal semen analysis does not mean everything is fine — it only checks count, motility, and morphology. It does not check DNA.
- Sperm DNA fragmentation is the single most important test most men never get
- HbA1c (blood sugar) directly damages sperm DNA — even in men without a diabetes diagnosis
- Elevated A1c is linked to poor morphology, low fertilization rates, and failed embryo development
- In my opinion my partner's elevated A1c played a significant role in our fertility journey — the correlation between his A1c, his morphology, and our fertilization rates across three cycles is striking
- Sperm takes 74 days to fully develop — start supplements and lifestyle changes at least 3 months before retrieval
- You can order HbA1c yourself — sperm DNA fragmentation requires a physician order but there are affordable options
- A man can significantly improve his sperm health in 3 to 6 months with targeted lifestyle and supplement changes
Why It Matters
Our Real Story — Why This Section Exists
In 2022 my partner's semen analysis looked acceptable. Nobody ordered an HbA1c. We made embryos and things didn't go the way we hoped.
By January 2025 — after our second retrieval at a different clinic that also never tested his blood sugar — his A1c came back at 13.1% at a routine PCP visit. Fully diabetic. It had likely been climbing since 2022 when it was already 6.4% — prediabetic range — and nobody flagged it at either clinic.
Before our third retrieval at CNY in 2026 he brought his A1c down to 5.3% through diet, exercise, and targeted supplementation. His morphology went from 1.8% to 7%. Our fertilization rate went from 38% to 87%.
Same woman. Similar number of eggs. In my opinion the most significant variable that changed was sperm health. I cannot prove causation — but the correlation is hard to ignore.
As Scientific American reported in August 2026, the ASRM released new guidelines for recurrent miscarriage noting that sperm DNA fragmentation testing "may be considered" in cases of multiple pregnancy losses — their first acknowledgment in 14 years that male factor deserves more attention in recurrent loss cases.
The A1c and Sperm DNA Connection
Elevated blood sugar directly damages sperm DNA through oxidative stress. You don't have to be diabetic for this to matter — prediabetes and insulin resistance can affect sperm DNA integrity too.
Men with elevated blood sugar consistently show higher sperm DNA fragmentation. A study directly comparing DNA quality in sperm from diabetic versus non-diabetic men found the percentage of fragmented DNA was significantly higher in diabetic men — 52% versus 32%. And this damage won't show up on a standard semen analysis at all.
A standard semen analysis checks count, motility, and morphology. It does not check DNA. A man can pass a semen analysis with flying colors and still have significant sperm DNA damage.
The Three-Cycle Data
In my opinion this data tells a clear story about the relationship between sperm health and IVF outcomes. I cannot prove causation — but I strongly believe my partner's A1c played a significant role in our journey. The numbers speak for themselves.
The Bigger Point
When a transfer fails, the conversation almost always turns to the woman. Her uterus. Her embryo. Her body.
But if the woman's side has been optimized and things still aren't working — sperm DNA health is a legitimate and underinvestigated variable. Particularly in cases where embryos fail to develop to blastocyst, fertilization rates are poor, or PGT-normal embryos keep failing.
An informed IVF patient asks about both partners. Always.